Lifting devices

ABSTRACT

A lifting and transporting device for gas cylinders and other heavy objects has a wheeled base frame provided with an upwardly extending column on which is slidably mounted a tubular member of an upper frame formed with manually operated jaws for clamping a cylinder in an upright position against the upper frame. A handlever pivotally mounted on the base frame is provided at its lower end with a roller which is adapted to engage a block mounted on the tubular member of the upper frame to lift the latter and the block carries a rotatable catch and catchoperating device of which the latter is rotated by a stop on the base column during upward movement of the upper frame to move the catch into locking engagement with the column and is further rotated by upward movement of the upper frame beyond its raised position to disengage the catch.

United States Patent Evans [4 Aug. 8, 1972 [54] LIFTING DEVICES 2,973,184 2/ 1961 Trautman ..254/2.4

72 Inventor: David L. E ans 250 C t' 1 Bristol 3 a g orona on Primary Examiner--Gerald M. P01181118.

Assistant Examiner-George F. Abraham Flled! 1970 Attorney-Norris & Bateman [21] Appl. No.: 7,700

I [57] ABSTRACT 30 Foreign Application priority Data A lifting and transporting device for gas cylinders and other heavy ob ects has a wheeled base frame pro- 1969 Great m "6965/69 vided with an upwardly extending column on which is Great Bmam 20,265/69 slidably mounted a tubular member of an upper frame formed with manually operated jaws for clamping a [52] US. CL... 2144653, 254/2 R, l87/76, cylinder in an upright position against the upper 294/1 15 frame. A hand-lever pivotally mounted on the base 1].. Cl. frame is provided at lower end a roller which [58] g z 3 is adapted to engage a block mounted on the tubular 9/11 memberoftheupperframetoliftthelatterandthe block carries a rotatable catch and catch-operating [56] References C'ted device of which the latter is rotated by a stop on the UNITED STATES PATENTS base column during upward movement of the upper frame to move the catch into locking engagement with 3,109,516 11/1963 Leo et al ..l87/76 the column and i flu-ther rotated by upward move 2,654,632 10/1953 Herbert ..294/1 16 mam of the upper frame beyond its raised position to 1,640,297 8/1927 Rogers ..2l4/33l disengage the catchv 2,536,614 1/1951 Syracusa ..2l4/1 D 2,993,703 7/1961 Paradise ..254/2.6 X 5 Claims, 4 Drawing Figures PATENTED 8 I97? 3. 682.342

sum 1 0F 4 INVENTOR DAVID LLEWELLYN EVANS ATTORNEYS: 4 m

PATENTED 8 I972 3. 682 342' SHEET 2 BF 4 INVEN'lUh DAVID LLEWELLYN EVANS ATTORNEYS J PATENJ'EDAUE 8 m2 3.682.342

sum 3 or 4 INVENTOR DAVID LLEWELLYN v EVANS xwmxmx-zys: 4' M PATENTEDMJE 8 1912 3,682,342

saw u or 4 IN'VENTOR DAVID LLEWELLYN EVANS ATTORNEYS:

LIFTING DEVICES This invention relates to lifting devices of the kind comprising a base frame for engagement with a supporting surface, an upper frame reciprocably mounted on said base frame for engagement with an object to be lifted and operating means for raising said upper frame relative to said base frame.

One object of the present invention is to provide a manually operated device of the kind described capable of lifting and transporting heavy objects, such as gas cylinders for use in hospitals and for industrial purposes, quickly, safely and with a minimum of effort and to this end, according to one aspect of the invention, there is provided a device for lifting and transporting heavy objects comprising a lower frame having ground wheels, an upper frame slidable vertically on said lower frame and provided with manually operable means for clamping an object thereto, a manually operated lever pivotally mounted on said lower frame for movement about a horizontal axis to raise said lower frame, and releasable means for locking said upper frame in its raised position.

Another object of the present invention is to provide a lifting device of the kind described with means for automatically retaining the upper frame in its raised position without the continued exertion of pressure on the operating means and to this end, according to a further aspect of the invention, there is provided a catch and a catch-operatingmember secured to a freely rotatable pivot on said upper frame and a stop member projecting from said base frame into the path of upward movement of said catch-operating member to rotate the latter, and thus the catch, into a position in which the catch engages said base frame and prevents downward movement of the upper frame.

Both aspects of the invention will be described, by way of example, with reference to the accompanying drawings which show a device for lifting and transporting heavy cylindrical objects such as gas cylinders, and' in which:

FIG. 1 is a side elevation of the device;

FIG. 2 is an end elevation of the device looking from the right-hand side of FIG. 1;

FIG. 3 is a plan view of the device; and

FIG. 4 is a part-sectional side elevation on an enlarged scale of a part of the device. 7 1

As shown, a base frame I mounted on fixed castors 2 and swivel castors 3 is cut away at 4 (FIG. 3) to accommodate the lower end of an upright gas cylinder (not shown). The base frame 1 carries an upright member 5 (FIG. 4) on which is slidably mounted a tubular member 6 of an upper frame 7 which supports a guide box 8 for a lead screw 9 (FIG. 1) passing through a nut 10, trapped against axial movement between the box 8 and the member 6. The lead screw 9 is provided with a hand-wheel 11 and carries a block (not shown) which slides in the box 8 and carries a pin 12 which extends through a slot (not shown) in a top plate 13 and is secured to a plate 14 which is slidably mounted on the plate 13. The plate 14 is formed with protuberances 15 (FIG. 3) which engage the backs of two jaws 16 which are pivoted on a pin 17 mounted in the stem 18 of a T- shaped member the cross-bar 19 of which bridges the plate 14 as shown in FIG. 2. Upon rotation of the handwheel 11 in one direction the jaws 16 can be closed through the medium of the lead screw 9 and plate 14 to clamp the upper end of an upright gas cylinder accommodated at its lower end in the cutaway portion 4 of the base frame 1 and resting against a rubber pad 20 (FIG. 1) on the front surface of the tubular member 6 and a stop 21 on the stem 18 of the T- shaped member. Upon rotation of the hand-wheel 11 in the opposite direction the jaws 16 are opened by tension springs 48 anchored at 49 and to the jaws l6 and the plate 13 respectively. Secured to the rear surface of the member 6 is a block 22 the lower end of which is engaged by a roller 23 rotatably mounted at the lower end of a hand-level 24 which is pivoted at 25 in a bracket 26 mounted on the base frame 1. Movement of the lever 24 about its pivot 25 in a clockwise direction as looked at in FIG. 1 acts throughthe block 22 to raise the tubular member 6 and with it the frame 7 and thus lift a gas cylinder clamped thereto clear of the ground to enable it to be transported from one location to another, while movement of the lever 24 in the anti-clockwise direction permits the frame 7 to return to its lowered position in which the lower end of the gas cylinder rests on the ground.

In order to lock the upper frame 7 in its raised position the block 22 is provided with a catch 27 and a catch-operating member 28 both secured to a pivot bolt 29 which is rotatably mounted in the block. The tubular frame member 6 is formed with a vertically extending slot 30 (FIG. 4) through which the catch 27 projects into engagement with the rear surface of the upright member 5 and through which a stop member 32 projects into the path of the catch-operating member 28. Below the stop member 31 the rear surface of the upright member 5 is cut away to provide an upwardly facing shoulder 32 which is adapted to be engaged by a projection 33 on the catch 27 when the latter is rotated by the catch-operating member 28 as a consequence of its engagement with the stop member when the tubular member 6 reaches its raised position shown in full lines inFIG. 4. The inter-engagement of the catch 27 and the shoulder 32 serves to prevent downward movement of the tubular member 6 when the hand-lever 24 is released. To release the catch 27 the hand-lever 24 is moved further in a clock-wise direction, as looked at in FIG. 1, whereupon the catch operating member 28 is further rotated by the stop member 31 to move the projection 33 on the catch 27 out of alignment with the shoulder 32 whereupon the tubular member 6 and with it the upper frame 7 can be ends of which are anchored to the bar 35 and to a pin 40 on the tube 36 respectively. The bar 35 is formed with a recess 41 to receive the end of a lever 42 which passes through registering slots in the base frame 1 and tube 36 and is pivoted at 43 on a bracket 44 (FIG. 1) mounted on the base frame 1. When the upper frame 7 is in its lowered position the return spring 38 holds the support 34 in the retracted position shown in FIG. 1 and in broken lines in FIG. 4. As the upper frame 7 is lifted a projection 45 (FIG. 4) on the rotating catch 27 engages the upper end of the lever 42, which moves in a clockwise direction, as looked at in FIGS. 1 and 4,

about its pivot 43 and moves the bar 35 to the left to place the support 34 beneath the lower end of a gas cylinder clamped to the upper frame. That part of the lever 42 which is engaged by the catch 27 takes the form of a block 46 (FIG. 4) which can yield against the action 'of a spring 47 should an attempt be made to clamp a cylinder to the device in the raised position of the upper frame 7 thus putting excessive pressure on the support 34 and bar 35.

In operation, the device is wheeled towards a cylinder or other object to be moved until the latter rests against the pad and stop 21. The jaws 16 are then closed upon the upper part of the cylinder by rotation of the hand-wheel 11 following which the cylinder is lifted by operation of the hand-lever 24 until the catch 27 makes locking engagement with the shoulder 32 on the member 5. The hand-lever 24 can then be returned to its original position and used for pulling the device to the point at which the cylinder is to be unloaded. Upon reaching this point the hand-lever 24 is again operated to release the catch 27 and is then moved in the opposite direction to enable thecylinder to be lowered to the ground following which the jaws 16 are opened by rotation of the release the cylinder.

Although the locking mechanism has been described with reference to a device for moving cylinders it will be obvious that it is applicable tO many other forms of lifting device employing relatively moving parts.

I claim:

1. A lifting device comprising a base frame, an upper frame reciprocably mounted on said base frame for enhand-wheel 11 to gagement with an object to be lifted, operating means for raising said upper frame relative to said base frame, a catch and a catch-operating member secured to a freely rotatable pivot on said upper frame and a stop member projecting from said base frame into the path of upward movement of said catch-operating member to rotate the latter and thus the catch, into a position in which the catch engages said base frame and prevents downward movement of said upper frame.

2. A lifting device according to claim 1, wherein said catch, said catch-operating member and said stop member are so arranged that upon further upward movement of said upper frame beyond its raised position said catch-operating member is further rotated by said stop member through an angle sufficient to disengage said catch from said base frame.

3. A manually-operable device for lifting and transporting heavy objects, comprising a base frame having ground wheels, a fixed guide member extending vertically upward from said base frame, an upper frame supported by a tubular member which surrounds and is slidable vertically along said guide member, manually operable means on said upper frame for clamping an object thereto, means for raising said upper frame comprising a manually operable lever pivotally mounted at a point close to its lower end on said base frame for movement about a horizontal axis relative thereto and releasable means for locking said upper frame in its raised position comprising a catch movably mounted on said tubular member and an abutment mounted on said guide member in the path of said catch and operable upon upward movement of said tubular member relative to said guide member to move said catch into locking engagement with a shoulder on said guide member.

4. A manually-operated device for lifting and transporting heavy objects, comprising a base frame having ground wheels, an upper frame slidable vertically on said base frame and provided with manually operable means for clamping an object thereto, a manually operated lever pivotally mounted on said base frame for movement about a horizontal axis to raise said upper frame, releasable means for locking said upper frame in its raised position, a bar longitudinally slidable in said base frame and provided at one end with a support for the lower end of an object clamped to said upper frame, a spring operative upon said bar to retract the said support within said base frame, and a lever pivotally mounted on said base frame with its lower end operatively engaging said bar and operable upon upward movement of said upper frame to move said bar into a position in which said support underlies the lower end of said object.

5. A manually-operable device as defined in claim 3, wherein said clamping means comprises a pair of jaws pivotally mounted on said upper frame for movement about a common vertical axis and urged into open position by tension springs each secured at its ends to one of said jaws and said upper frame,respectively, an operating plate horizontally slidably mounted on said upper frame and having laterally spaced portions separately engaging the backs of the respective jaws and a lead screw and nut mechanism operable by a rotary handle for moving said operating plate in a direction to close said jaws. 

1. A lifting device comprising a base frame, an upper frame reciprocably mounted on said base frame for engagement with an object to be lifted, operating means for raising said upper frame relative to said base frame, a catch and a catch-operating member secured to a freely rotatable pivot on said upper frame and a stop member projecting from said base frame into the path of upward movement of said catch-operating member to rotate the latter and thus the catch, into a position in which the catch engages said base frame and prevents downward movement of said upper frame.
 2. A lifting device according to claim 1, wherein said catch, said catch-operating member and said stop member are so arranged that upon further upward movement of said upper frame beyond its raised position said catch-operating member is further rotated by said stop member through an angle sufficient to disengage said catch from said base frame.
 3. A manually-operable device for lifting and transporting heavy objects, comprising a base frame having ground wheels, a fixed guide member extending vertically upward from said base frame, an upper frame supported by a tubular member which surrounds and is slidable vertically along said guide member, manually operable means on said upper frame for clamping an object thereto, means for raising said upper frame comprising a manually operable lever pivotally mounted at a point close to its lower end on said base frame for movement about a horizontal axis relative thereto and provided at its lower end with means for engagement beneath a block secured to said tubular member, and releasable means for locking said upper frame in its raised position comprising a catch movably mounted on said tubular member and an abutment mounted on said guide member in the path of said catch and operable upon upward movement of said tubular member relative to said guide member to move said catch into locking engagement with a shoulder on said guide member.
 4. A manually-operated device for lifting and transporting heavy objects, comprising a base frame having grouNd wheels, an upper frame slidable vertically on said base frame and provided with manually operable means for clamping an object thereto, a manually operated lever pivotally mounted on said base frame for movement about a horizontal axis to raise said upper frame, releasable means for locking said upper frame in its raised position, a bar longitudinally slidable in said base frame and provided at one end with a support for the lower end of an object clamped to said upper frame, a spring operative upon said bar to retract the said support within said base frame, and a lever pivotally mounted on said base frame with its lower end operatively engaging said bar and operable upon upward movement of said upper frame to move said bar into a position in which said support underlies the lower end of said object.
 5. A manually-operable device as defined in claim 3, wherein said clamping means comprises a pair of jaws pivotally mounted on said upper frame for movement about a common vertical axis and urged into open position by tension springs each secured at its ends to one of said jaws and said upper frame,respectively, an operating plate horizontally slidably mounted on said upper frame and having laterally spaced portions separately engaging the backs of the respective jaws and a lead screw and nut mechanism operable by a rotary handle for moving said operating plate in a direction to close said jaws. 